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Hemi rear main/426 #1897223 08/22/15 06:30 PM 08/22/15 06:30 PM
Joined: Mar 2005 Posts: 2,060 Pendleton NY T terzmo OP top fuel
terzmo OP top fuel T Joined: Mar 2005 Posts: 2,060 Pendleton NY	New 91 chrysler 426 block...installed rear main before installing new motor and leaked ALOT..replaced again with rubber seal and two side pieces of non rubber material and still leaking but not as bad..molnar crank..not knurled.....crank did need alot of weight to balance if that means anything.....anyone suggest a good rear main seal for this application. Thanks moparts Thanks in advance to all

Re: Hemi rear main/426 [Re: terzmo] #1897228 08/22/15 06:37 PM 08/22/15 06:37 PM
Joined: Jan 2003 Posts: 25,777 Rio Linda, CA John_Kunkel Too Many Posts
John_Kunkel Too Many Posts Joined: Jan 2003 Posts: 25,777 Rio Linda, CA	Is the aluminum seal retainer new or used? Many used retainers are distorted from having the rope seal pounded into them and won't grip a Neoprene seal correctly. The INTERNET, the MISinformation superhighway

Re: Hemi rear main/426 [Re: John_Kunkel] #1897268 08/22/15 07:59 PM 08/22/15 07:59 PM
Joined: Mar 2005 Posts: 2,060 Pendleton NY T terzmo OP top fuel
terzmo OP top fuel T Joined: Mar 2005 Posts: 2,060 Pendleton NY	all new.....rubber seal used...no rope

Re: Hemi rear main/426 [Re: terzmo] #1897281 08/22/15 08:22 PM 08/22/15 08:22 PM
Joined: Jan 2003 Posts: 27,467 So Cal autoxcuda Too Many Posts
autoxcuda Too Many Posts Joined: Jan 2003 Posts: 27,467 So Cal	What brand aluminum seal retainer did you use? Try a rope seal. That fixed the one in Troy's MP block with aftermarket crank.

Re: Hemi rear main/426 [Re: terzmo] #1897285 08/22/15 08:38 PM 08/22/15 08:38 PM
Joined: Aug 2013 Posts: 152 usa S smos001 member
smos001 member S Joined: Aug 2013 Posts: 152 usa	Avoid the rope seal. Rope seals were not put into motors in the late 60s and 70s. Rope seals are a band aid and will eventually leak. You need to find out why it's leaking. I spent a year researching rear main seals. lots of urban legends out there; knurling, no knurling, etc. Mine was leaking because of the retainer bolts were offset by a fraction to one side (defect in manufacturing). Enough offset not to seal around the crank. I shimmed it the exact amount that was needed to center the retainer on the crank. Dry since the rebuild over 1300 miles so far without a drip. Do the math. Measure everything. Find out if it is leaking from the sides or around the crank. If it's the crank, you need to pull the weak side seal toward the crank. There is a good procedure for this. I wrote something up awhile ago on this. I pulled my engine apart 4 times. After pulling out the micrometer and snap gauges we found the issue. Rear main seals don't leak because of magic. It's math. Last edited by smos001; 08/22/15 08:39 PM.

Re: Hemi rear main/426 [Re: smos001] #1897286 08/22/15 08:44 PM 08/22/15 08:44 PM
Joined: Jan 2003 Posts: 27,467 So Cal autoxcuda Too Many Posts
autoxcuda Too Many Posts Joined: Jan 2003 Posts: 27,467 So Cal	Originally Posted By smos001 Avoid the rope seal. Rope seals were not put into motors in the late 60s and 70s. .... You sure about that? I've pulled them out of original never apart late 60's early 70's motors.

Re: Hemi rear main/426 [Re: smos001] #1897297 08/22/15 09:14 PM 08/22/15 09:14 PM
Joined: Mar 2005 Posts: 2,060 Pendleton NY T terzmo OP top fuel
terzmo OP top fuel T Joined: Mar 2005 Posts: 2,060 Pendleton NY	Originally Posted By smos001 Avoid the rope seal. Rope seals were not put into motors in the late 60s and 70s. Rope seals are a band aid and will eventually leak. You need to find out why it's leaking. I spent a year researching rear main seals. lots of urban legends out there; knurling, no knurling, etc. Mine was leaking because of the retainer bolts were offset by a fraction to one side (defect in manufacturing). Enough offset not to seal around the crank. I shimmed it the exact amount that was needed to center the retainer on the crank. Dry since the rebuild over 1300 miles so far without a drip. Do the math. Measure everything. Find out if it is leaking from the sides or around the crank. If it's the crank, you need to pull the weak side seal toward the crank. There is a good procedure for this. I wrote something up awhile ago on this. I pulled my engine apart 4 times. After pulling out the micrometer and snap gauges we found the issue. Rear main seals don't leak because of magic. It's math. I guess I'm looking for the "magic" seal as I don't want to pull,tear the engine apart and measure. Glad yours worked. Thanks ANd for the rope seal...who has one ?

Re: Hemi rear main/426 [Re: terzmo] #1897301 08/22/15 09:16 PM 08/22/15 09:16 PM
Joined: Jan 2003 Posts: 27,467 So Cal autoxcuda Too Many Posts
autoxcuda Too Many Posts Joined: Jan 2003 Posts: 27,467 So Cal	Read here on the rope seal Troy put in his Hemi: https://board.moparts.org/ubbthreads/ubbthreads.php/topics/1102381/1.html

Re: Hemi rear main/426 [Re: terzmo] #1897312 08/22/15 09:50 PM 08/22/15 09:50 PM
Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska R RapidRobert Circle Track
RapidRobert Circle Track R Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska	Quote: ANd for the rope seal...who has one ? Car quest JV551 Victor Reinz brand EDIT listed for a SB but you'll trim it to fit just like a BB install (not sure why it would not be listed for a BB). comes with a tube of silicone Last edited by RapidRobert; 08/23/15 01:33 AM. live every 24 hour block of time like it's your last day on earth

Re: Hemi rear main/426 [Re: RapidRobert] #1897484 08/23/15 01:25 AM 08/23/15 01:25 AM
Joined: Feb 2003 Posts: 8,020 Pangaea B5 Bee master
B5 Bee master Joined: Feb 2003 Posts: 8,020 Pangaea	Rope seals work best with the knurling, such as the OEM cranks. Neoprene is best on smooth journals like many aftermarket cranks have.

Re: Hemi rear main/426 [Re: terzmo] #1897495 08/23/15 01:39 AM 08/23/15 01:39 AM
Joined: Aug 2013 Posts: 152 usa S smos001 member
smos001 member S Joined: Aug 2013 Posts: 152 usa	My engine builder said they phased out rope seals by the late 60s and 70s. But I will do some more research on that. I hate to re-write history. ...so I will do some research. The key here is avoiding the frustration of doing a rear main seal twice or more times is to find the answer to "why" it is leaking. Just replacing it with "something" may lead to frustration down the road. I honestly would do some detective work. I know it is a pain with the engine in the car. I'm not sure I would not just change everything and hope also. But if you can look at the upper seal against the crank it may give you some clues. Last edited by smos001; 08/23/15 01:41 AM.

Re: Hemi rear main/426 [Re: smos001] #1897546 08/23/15 09:45 AM 08/23/15 09:45 AM
Joined: Nov 2012 Posts: 60 Maryland G gofastboater member
gofastboater member G Joined: Nov 2012 Posts: 60 Maryland	I always use a "seasoned" oil seal retainer. Never had a problem. Always used rubber seal.

Re: Hemi rear main/426 [Re: terzmo] #1897694 08/23/15 02:26 PM 08/23/15 02:26 PM
Joined: Aug 2013 Posts: 152 usa S smos001 member
smos001 member S Joined: Aug 2013 Posts: 152 usa	Here maybe your magic seal: http://www.fastfishautoparts.com/Performance-Engine-Seals.html It's a new one piece rear seal. I believe you make one cut in it. You will probable have to fish it up through the block and then the retainer. Good luck,

Re: Hemi rear main/426 [Re: B5 Bee] #1897853 08/23/15 07:30 PM 08/23/15 07:30 PM
Joined: Jan 2003 Posts: 4,105 Horsham, Pa. Finoke master
Finoke master Joined: Jan 2003 Posts: 4,105 Horsham, Pa.	Originally Posted By B5 Bee Rope seals work best with the knurling, such as the OEM cranks. Neoprene is best on smooth journals like many aftermarket cranks have. I agree! Went to a rope seal on my knurled hemi crank. No issues now. The lip seal leaked like a sieve.

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